From 23d3980b6cfea4e9056d9b7b81e48b4fefc645e0 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 7 May 2013 11:46:18 -0400 Subject: [PATCH] mountd: Fix is_subdirectory again The problem was that is_subdirectory() would also succeed if the two directories were the same. This is needed for path_matches() which needs to see if the child is same-or-descendant. So this patch rearranges path_matches() to do the "are they the same" test itself and only bother with is_subdirectory() if it they are not the same. So now is_subdirectory() can be strict, and so can be usable for subexport(), which needs a strong 'in subdirectory - not the same' test. Acked-by: J. Bruce Fields Signed-off-by: NeilBrown Signed-off-by: Steve Dickson --- utils/mountd/cache.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c index 737927c..517aa62 100644 --- a/utils/mountd/cache.c +++ b/utils/mountd/cache.c @@ -347,20 +347,26 @@ static char *next_mnt(void **v, char *p) static int is_subdirectory(char *child, char *parent) { + /* Check is child is strictly a subdirectory of + * parent or a more distant descendant. + */ size_t l = strlen(parent); - if (strcmp(parent, "/") == 0) + if (strcmp(parent, "/") == 0 && child[1] != 0) return 1; - return strcmp(child, parent) == 0 - || (strncmp(child, parent, l) == 0 && child[l] == '/'); + return (strncmp(child, parent, l) == 0 && child[l] == '/'); } static int path_matches(nfs_export *exp, char *path) { - if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) - return is_subdirectory(path, exp->m_export.e_path); - return strcmp(path, exp->m_export.e_path) == 0; + /* Does the path match the export? I.e. is it an + * exact match, or does the export have CROSSMOUNT, and path + * is a descendant? + */ + return strcmp(path, exp->m_export.e_path) == 0 + || ((exp->m_export.e_flags & NFSEXP_CROSSMOUNT) + && is_subdirectory(path, exp->m_export.e_path)); } static int @@ -369,15 +375,13 @@ export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai) return path_matches(exp, path) && client_matches(exp, dom, ai); } -/* True iff e1 is a child of e2 and e2 has crossmnt set: */ +/* True iff e1 is a child of e2 (or descendant) and e2 has crossmnt set: */ static bool subexport(struct exportent *e1, struct exportent *e2) { char *p1 = e1->e_path, *p2 = e2->e_path; - size_t l2 = strlen(p2); return e2->e_flags & NFSEXP_CROSSMOUNT - && strncmp(p1, p2, l2) == 0 - && p1[l2] == '/'; + && is_subdirectory(p1, p2); } struct parsed_fsid { -- 1.8.3.2